[单项选择]

Children attending schools located in high-traffic zones have a 45 percent increased risk of developing asthma, even though time spent at school only accounts for about one-third of a child’s waking hours, according to new research.
Asthma is the most common chronic childhood illness in developed countries and has been linked to environmental factors such as traffic-related air pollution. "While residential traffic-related pollution has been associated with asthma, there has been little study of the effects of traffic exposure at school on new onset asthma," says Rob McConnell, professor of preventive medicine at USC’s Keck School of Medicine. "Exposure to pollution at locations other than home, especially where children spend a large portion of their day and may engage in physical activity, appears to influence asthma risk as well."
The study appears online in the journal Environmental Health Perspectives. The study drew upon data
A. There exists traffic-related pollution
B. Schools are located in heavy-traffic areas
C. Children are frequently exposed to pollution
D. The vehicles increase rapidly

[单项选择]Children attending schools located in high-traffic zones have a 45 percent increased risk of developing asthma, even though time spent at school only accounts for about one-third of a child’s waking hours, according to new research.
Asthma is the most common chronic childhood illness in developed countries and has been linked to environmental factors such as traffic-related air pollution. "While residential traffic-related pollution has been associated with asthma, there has been little study of the effects of traffic exposure at school on new onset asthma," says Rob McConnell, professor of preventive medicine at USC’s Keck School of Medicine. "Exposure to pollution at locations other than home, especially where children spend a large portion of their day and may engage in physical activity, appears to influence asthma risk as well."
The study appears online in the journal Environmental Health Perspectives. The study drew upon data from the Children’s Health Study (CHS),
A. There exists traffic-related pollution.
B. Schools are located in heavy-traffic areas.
C. Children are frequently exposed to pollution.
D. The vehicles increase rapidly.

[填空题]The majority of children attend state schools where the tuition is free but parents need to pay for stationery, books, examination fees, school uniform and sports wear and other boarding and lodging.

[单项选择]Why did children not need formal schools for a long while
A. The teachers came to the children’ s homes.
B. The children acquired the information they needed by direct experience.
C. Children were taught in small, personalized groups at home.
D. Parents would teach children the three R’ s themselves.